Rigid, thermoplastic food containers are generally known. These containers are substantially airtight when fully closed. Numerous types of bowl and lid assemblies and means for effecting sealable engagement of a lid on a bowl have been devised. Illustrative are the containers and engagement means disclosed in U.S. Pat. No. 6,170,696. One type of container is a spin lock container as described in U.S. Pat. No. 7,523,839, where the cover is secured to the base with a rotational threaded mechanism.
Consumers often desire to carry two separate items in a storage container. For example, a consumer may store a salad in one storage container and salad dressing in a separate container. Conventional solutions for providing a single storage device for holding multiple items have been proposed. U.S. Patent Publication No. 2007/0102319 describes a one-piece container having a first vessel and a second vessel permanently secured to and inside the first vessel. In this design, the user may not be able to, for example, pour salad dressing out of the inner vessel without spilling the contents of the outer vessel. U.S. Pat. No. 6,302,268 describes a container having an insert chamber that may release its contents into the container through a hole in the bottom of the insert chamber. To fill the insert chamber, it must be removed from the lid of the container, filled, capped and inserted, cap side down, back into the container. When the insert chamber is not in use, it must remain in place in the lid of the container, else the lid of the container would have an opening and not seal the contents within the container.
Accordingly, it would be advantageous to provide containers that address some of the problems of conventional food containers, which lack the ability to controllably ensure complete sealing of the container while providing the convenience of a removable inner container attachable to the spin-on cover.